Digital isolation barrier as interface bus for modems

ABSTRACT

The present application provides a variety of exemplary embodiments, such as modem systems, modem devices, modem connectors, host connectors, communication systems and communication cards. For example, there is provided a modem device for use to enable a host to communicate over a communication line, wherein the host has a host connector. The modem device comprises a line side circuitry capable of interfacing with the communication line; and a digital isolation barrier (DIB) coupled to the line side circuitry, the digital isolation barrier capable of being connected to a modem connector for connection to the host connector, wherein the digital isolation barrier is capable of isolating the modem connector from the line side circuitry. Moreover, the line side circuitry may include a line side DIB interface for communication with the digital isolation barrier. Also, the modem connector may be connected to the digital isolation barrier via one or more lines.

INCORPORATION BY REFERENCE

[0001] The commonly-assigned U.S. Pat. No. 6,351,530, issued Feb. 26,2002, is hereby incorporated by reference in its entirety, includingdrawings and appendices, into the present application and is hereby madepart of the present application for all purposes.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to modems and, moreparticularly, to the use of a digital isolation barrier as a digitalcommunication bus between a modem and a host.

[0004] 2. Related Art

[0005] As in other computer-related areas of technology, the modemtechnology has been on a rapid pace of change and progress, and hasevolved tremendously since about just two decades ago. Modem (orModulator/Demodulator) is a device that adapts a host, such as aterminal or computer to a communication medium, such as an analogtelephone line, by converting digital pulses to audio frequencies andvice versa. The term modem also refers to and encompasses cable or DSLmodem or ISDN terminal adapter for purposes of the present invention.Also, for purposes of the present invention, a host includes anyinformation handling system, such as a computer, set-top box, gameconsole or any other device or system that utilizes the modem tocommunicate via the communication medium.

[0006]FIG. 1A provides a glance at the modem evolution throughout therecent years. As shown, in one conventional embodiment, modem 100communicates data with host 101, such as a terminal or a computer, indigital format, via modem side bus interface 104. As shown, host 101includes host bus/connector 103, which provides a connection betweenhost 101 and modem 100 via host side bus interface 102 and modem sidebus interface 104. Modem 100 is further capable of communicating with aremote device, in analog format, via telephone network 108. Telephonenetwork 108 may be part of a public switched telephone network (“PSTN”).It should be noted that, throughout the present application the terms“bus” and “connector”, may be used interchangeably, and either termrefers to any type of conductor or channel that is capable of providinga communication path.

[0007] Modem 100 depicts an early modem design, which is known as acontroller-based modem. As shown, modem 100 includes controller 105,digital signal processor (“DSP”) 106 and data access arrangement (“DAA”)107. In such design, controller 105 controls all the modem functions andmodem components, including DSP 106 and DAA 107. Controller 105 alsocontrols modem side bus interface 104. Controller can be any type ofmicroprocessor, such as a Rockwell 6502-based processor. Controller 105executes instructions residing in a memory device (not shown), such asan EPROM, which stores the modem software. According to the instructionsstored in the memory, controller 105 is able to control DSP 106, DAA 107and modem side bus interface 104. DSP 106 performs the task ofmodulating signals received via modem side bus interface 104 andtransmitting the modulated signals to DAA 107 for digital to analogconversion and transmission over the telephone line. Further, DSP 106demodulates signals received from DAA 107 after analog to digitalconversion by DAA 107 and provides the demodulated signals fortransmission over modem side bus interface 104 to host 101.

[0008] DAA 107 generally refers to circuitry, which provides aninterface with a telephone line originating from the telephone centraloffice. DAA 107 electrically isolates the rest of modem 100 from thetelephone line. For example, DAA 107 provides galvanic isolation toprevent voltage surges or transients originating from modem 100 fromhaving a deleterious effect on telephone network 108. Electricalisolation also addresses potential problems associated with differencesin operating voltages between the telephone line and modem 100. Moreparticularly, telephone line voltages may vary widely across a givennetwork, and often exceed the operating voltage of modem 100. Inaddition to electrical isolation, DAA 107 often provides a variety ofsignals, such as a ring signal for use by modem 100.

[0009] As a next generation of modems, controllerless modem 110 wasintroduced, which includes modem side bus interface 114, DSP 116 and DAA117, but not a controller, for use to enable host 111 to communicateover telephone network 118. In such designs, a host controller (notshown) residing in host 111 controls controllerless modem 110 via hostside bus interface 112, which may be connected to modem side businterface 114 via host bus 113. DSP 116 and DAA 117 perform similarfunctions as DSP 106 and DAA 107, respectively.

[0010] Turning to a more recent generation of modems, soft modem 120includes DAA 127, but neither a controller nor a DSP, for use to enablehost 121 to communicate over telephone network 128. According to thesoft modem design, a host controller (not shown) residing in host 121provides DSP functionality and further controls soft modem 120 via hostside bus interface 122, which may be connected to modem side businterface 124 via host bus 123. DAA 127 performs similar functions asDAA 107 and DAA 117.

[0011] Such existing modem configurations, however, introduce manydrawbacks, inefficiencies and excessive costs when such modems aresubmitted for homologation or approval by regulatory agencies throughoutthe world, which have established standards and regulations in eachcountry, for connecting subscriber equipment, such as a modem to atelephone network. The homologation procedures are intended to confirmcompliance with telephone standards and regulations in each country inorder to prevent damage to the telephone network and mitigateinterference with other equipment also connected to the telephonenetwork. The homologation procedures, however, often present difficultdesign challenges, can be lengthy and result in excessive costs to beincurred by applicants. For example, worldwide homologation typicallytakes between 6-12 months and can cost in the range of $100,000 to$200,000. Accordingly, modem homologation is a main source of costs,delays and engineering burden that must be endured by modemmanufacturers for each new modem design.

[0012] Turning to FIG. 1B, it illustrates an evolutionary block diagramof various conventional host or computer connectors/buses for modemcommunications. Originally, desktop computers provided a serialinterface, such as an RS-232 serial bus (Recommended Standard byTIA/EIA) 130, which later evolved into universal serial bus (“USB”).RS-232 serial bus 130 uses a 25-pin DB-25 or 9-pin DB-9 connector. Next,the Industry Standard Architecture (“ISA”) bus 131 was introduced invarious form factors to function as an expansion bus commonly used inpersonal computers. ISA bus 131 can accept plug-in boards that controlperipheral devices, such as modems. As a later generation of personalcomputer buses, Peripheral Component Interconnect (“PCI”) bus 132 wasintroduced, as a peripheral bus commonly used in personal computers. PCIbus 132 provides a high-speed data path between the host processor andperipheral devices, such as modem devices. There are typically three orfour PCI slots on a given motherboard.

[0013] A more recent personal computer bus is Audio/Modem Riser (“AMR”)bus 133 that supports a plug-in card into the motherboard that containsaudio and/or modem circuits. AMR bus is a 46-pin bus that provides thedigital interface between the card and the motherboard. AMR bus hasevolved into a Communications and Networking Riser (“CNR”) bus with a30-pin interface and an Advanced Communications Riser (“ACR”) bus with a106-pin interface. CNR and ACR provide additional support, such as LAN,DSL or Ethernet interface.

[0014] Similar personal computer buses have been introduced for laptopcomputers, such as ISA bus 140 with proprietary interfaces, PersonalComputer Memory Card International Association (“PCMCIA”) bus 141, MiniPCI bus 142, similar to PCI bus 122, and Mobile Daughter Card bus(“MDD”) 143, similar to AMR bus 133.

[0015] Existing personal computer buses for modem communications,however, suffer from many problems, such as too many connector pins,occupying too much space, and not being uniform in pin-outs andspecifications. As a result, various modem side bus interfaces (such asmodem side bus interfaces 103, 113 and 123) must be provided for eachmodem design for compliance with numerous bus standards. Therefore,excessive costs must be incurred and many hours of engineering effortsmust be spent to design and manufacture modems with various modem sidebus interfaces.

[0016] Furthermore, in the more recent years, as soft modems continue todisplace traditional hardware modems, such as modem 100 and modem 110,silicon DAAs have, as a result, been experiencing rapid growth. Asdiscussed above, DAAs are used as telephone line interfaces and arerequired in any device that connects to the telephone line or any othersimilar communication line. Traditionally, DAAs have been implemented inanalog modems, such as modem 100, as an assortment of transformers,relays, opto-isolators and discrete components. But, in order to reducethe high cost, power consumption and space associated with thetraditional DAAs, DAAs started to be designed for siliconimplementation, thus giving rise to silicon DAAs. Early on, silicon DAAsrelied on the transfer of analog signals across an isolation barrier andstill required many discrete components. Lately, however, silicon DAAsolutions utilize an integrated codec and transmit digital signalsacross capacitors to reduce cost, power consumption and space. Forexample, FIG. 1 of the commonly-assigned U.S. Pat. No. 6,351,530, issuedFeb. 26, 2002, which is incorporated by reference in the present patentapplication, illustrates an exemplary silicon DAA design. The DAAincludes a digital isolation barrier coupled to a system side circuitryat one end and to a line side circuitry at the other. Line sidecircuitry includes a digital isolation barrier interface and a codec,and is connected to a telephone line. Also, the system side circuitryincludes a digital isolation barrier interface and a host interface, andis connected to a host via a connector.

[0017] Today's silicon DAA solutions, however, still fail to insulatehost side components and the DAA. Therefore, clearance and creepage ofDAA components and other components must still be addressed during thedesign process, which require expert knowledge and cause additionalcosts and time to market delays. In addition, each new design includingthe DAA and the host side components, in combination, must be formallytested in accordance with the safety requirements and regulatoryhomologation regulations. Accordingly, a given silicon DAA must undergothe homologation process, in combination with the system in which thesilicon DAA has been designed into, over and over again, which, asstated above, causes a delay of about 6-9 months and costs of about$100,000-$200,000, for worldwide homologation.

SUMMARY OF THE INVENTION

[0018] In accordance with the purpose of the present invention asbroadly described herein, there is provided a variety of exemplaryembodiments, such as modem systems, modem devices, modem connectors,host connectors, communication systems and communication cards.

[0019] For example, in one aspect of the present invention, there isprovided a modem system for use to enable a host to communicate over acommunication line, wherein the host has a host connector. The modemsystem comprises: a line side circuitry capable of interfacing with thecommunication line; a digital isolation barrier (DIB) coupled to theline side circuitry; and a modem connector connected to the digitalisolation barrier and capable of connecting the digital isolationbarrier to the host connector, wherein the digital isolation barrierisolates the modem connector from the line side circuitry.

[0020] In another aspect, there is provided a modem device for use toenable a host to communicate over a communication line, wherein the hosthas a host connector. The modem device comprises: a line side circuitrycapable of interfacing with the communication line; and a digitalisolation barrier (DIB) coupled to the line side circuitry, the digitalisolation barrier capable of being connected to a modem connector forconnection to the host connector, wherein the digital isolation barrieris capable of isolating the modem connector from the line sidecircuitry.

[0021] In yet another aspect, there is provided a modem system for useto enable a host to communicate over a communication line, wherein thehost has a host connector. The modem system comprises: a communicationline receiver having an opening for receiving the communication line,the opening defining a plurality of side walls; a line side circuitrycapable of interfacing with the communication line receiver; and adigital isolation barrier (DIB) coupled to the line side circuitry, thedigital isolation barrier capable of being connected to a modemconnector, wherein the digital isolation barrier isolates the modemconnector from the line side circuitry; wherein the modem connector iscapable of being connected to the host connector, and wherein the linecircuitry and the digital isolation barrier populate one or more of theplurality of side walls.

[0022] In one aspect, there is provided a communication system capableof communicating over a communication line. The communication systemcomprises: a modem including a line side circuitry capable of beingconnected to the communication line, a digital isolation barrier (DIB)coupled to the line side circuitry and a modem connector coupled to thedigital isolation barrier; and a host including a modem connectorreceiving the modem connector, a host side DIB interface coupled to themodem connector, and a host processor coupled to the host side DIBinterface; wherein the host processor controls the modem.

[0023] In another aspect, there is provided a communication systemcapable of communicating over a communication line. The communicationsystem comprises: a modem including a line side circuitry capable ofbeing connected to the communication line, a digital isolation barrier(DIB) coupled to the line side circuitry and a modem connector coupledto the digital isolation barrier; and a host including a communicationcard, the communication card having a modem connector, for receiving themodem connector, and a host side DIB interface coupled to the modemconnector.

[0024] In an additional aspect of the present invention, there isprovided a communication card capable of connecting a host to a modem.The communication card comprises: a card-modem connector; a card-hostconnector capable of being connected to the host; wherein the modemincludes a line side circuitry capable of being connected to acommunication line, a digital isolation barrier (DIB) coupled to theline side circuitry and a modem connector coupled to the digitalisolation barrier, and wherein the card-modem connector is capable ofbeing connected to the modem connector.

[0025] In one more aspect, there is provided a modem connector forconnecting a modem to a host. The modem connector comprises: a data linefor communicating data between the modem and the host; wherein the modemincludes a line side circuitry capable of interfacing with thecommunication line, a digital isolation barrier (DIB) coupled to theline side circuitry, the digital isolation barrier capable of beingconnected to the modem connector for connection to the host connector,wherein the digital isolation barrier is capable of isolating the modemconnector from the line side circuitry.

[0026] In yet another aspect, there is provided a host connector forconnecting a modem to a host. The host connector comprises: a data linefor communicating data between the modem and the host; wherein the modemincludes a line side circuitry capable of interfacing with thecommunication line, a digital isolation barrier (DIB) coupled to theline side circuitry, the digital isolation barrier capable of beingconnected to the host connector for connection to the host, wherein thedigital isolation barrier is capable of isolating the host connectorfrom the line side circuitry.

[0027] In various aspects of the present invention, the line sidecircuitry may include a line side DIB interface for communication withthe digital isolation barrier. Moreover, in some aspects, the modemconnector may be connected to the digital isolation barrier via a singleline of data/control. In addition, the modem connector may be connectedto the digital isolation barrier via the single line of data/control andone ground line.

[0028] Also, the digital isolation barrier may be coupled to the lineside circuitry via a plurality of lines including two lines ofdata/control and two lines of power/clock, and the plurality of linesmay include a ground line. Yet, the modem connector may be connected tothe digital isolation barrier via a plurality of lines including twolines of data/control and two lines of power/clock, and the plurality oflines may include a ground line. Even more, the modem connector may beconnected to the digital isolation barrier via a single differentialpair of lines of data/control. Also, the modem connector may beconnected to the digital isolation barrier via the single differentialpair of lines of data/control and one ground line. Yet, in some aspects,the modem connector may be connected to the digital isolation barriervia a plurality of differential pair of lines of data/control. Also, insome aspects, the modem connector may be connected to the digitalisolation barrier via the plurality of differential pair of lines ofdata/control and one ground line.

[0029] In one exemplary aspect of the present invention, there isprovided a modem connector for connecting a modem to a host, wherein themodem includes a digital isolation barrier (DIB) coupled to a line sidecircuitry for communication with a communication line. The modemconnector comprises: a data line for communicating data between themodem and the host; a clock line for clocking the data between the modemand the host; and a power line for providing power from the host to themodem; wherein the data line, the clock line and the power line arecapable of being connected to the digital isolation barrier, which iscapable of isolating the modem connector from the line side circuitry.In addition, the data line may include a transmit path and a receivepath, or the data line may be a bi-directional path. Also, the host mayincludes a host side DIB interface, wherein the modem connector providesthe lines to host DIB interface. For example, the modem connector mayfurther comprise a four-wire cable including the lines or may furthercomprise a ground line.

[0030] In another exemplary aspect, there is provided a host connectorfor communication with a modem, the modem including a digital isolationbarrier (DIB) coupled to a line side circuitry for communication with acommunication line. The host connector comprises: a data line forcommunicating data between the modem and the host; a clock line forclocking the data between the modem and the host; and a power line forproviding power from the host to the modem; wherein the data line, theclock line and the power line are capable of being connected to thedigital isolation barrier, which is capable of isolating the hostconnector from the line side circuitry. Moreover, the data line mayinclude a transmit path and a receive path, or the data line is abi-directional path. In one aspect, the host may include a host side DIBinterface, wherein the host connector provides the lines to host DIBinterface. In addition, the modem connector may further comprise aground line.

[0031] These and other aspects of the present invention will becomeapparent with further reference to the drawings and specification, whichfollow. It is intended that all such additional systems, methods,features and advantages be included within this description, be withinthe scope of the present invention, and be protected by the accompanyingclaims.

BRIEF DESCRIPTION OF DRAWINGS

[0032] The features and advantages of the present invention will becomemore readily apparent to those ordinarily skilled in the art afterreviewing the following detailed description and accompanying drawings,wherein:

[0033]FIG. 1A illustrates an evolutionary block diagram of variousconventional modems;

[0034]FIG. 1B illustrates an evolutionary block diagram of variousconventional host connectors/buses for modem communications;

[0035]FIG. 2 illustrates a block diagram of a communication system,including a host and a modem with a line side circuitry, digitalisolation barrier and a modem connector, according to one embodiment ofthe present invention;

[0036]FIG. 3A illustrates a block diagram of the digital isolationbarrier of the communication system of FIG. 2;

[0037]FIG. 3B illustrates a diagram of an exemplary frame protocol forcommunicating information across the digital isolation barrier of FIG.3A, in accordance with one embodiment of the present invention;

[0038]FIG. 4 illustrates a block diagram of the line side circuitry ofthe communication system of FIG. 2;

[0039]FIG. 5 illustrates a block diagram of the host of thecommunication system of FIG. 2;

[0040]FIG. 6 illustrates a block diagram of an exemplary modem of thepresent invention for connection to a computer card;

[0041]FIG. 7 illustrates a block diagram of an exemplary modem of thepresent invention for connection to a computer motherboard;

[0042]FIG. 8A illustrates a full front view of an exemplary modem of thepresent invention, wherein the modem components are populated on atelephone line jack;

[0043]FIG. 8B illustrates a top view of an exemplary modem of thepresent invention, wherein the modem components are populated on top ofa telephone line jack; and

[0044]FIG. 9 illustrates a block diagram of an exemplary modem of thepresent invention for connection to a combo card.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0045] The present invention may be described herein in terms offunctional block components and various processing steps. It should beappreciated that such functional blocks may be realized by any number ofhardware components and/or software components configured to perform thespecified functions. For example, the present invention may employvarious integrated circuit components, e.g., memory elements, digitalsignal processing elements, transmitters, receivers, tone detectors,tone generators, logic elements, and the like, which may carry out avariety of functions under the control of one or more microprocessors orother control devices. Further, it should be noted that the presentinvention may employ any number of conventional techniques for datatransmission, signaling, signal processing and conditioning, tonegeneration and detection and the like. Such general techniques that maybe known to those skilled in the art are not described in detail herein.

[0046] It should be appreciated that the particular implementationsshown and described herein are merely exemplary and are not intended tolimit the scope of the present invention in any way. For example,although the present invention is described using an analog modem, thepresent invention may be implemented in other communication devicesinterfacing with any communication medium. Indeed, for the sake ofbrevity, conventional analog circuit, circuit components, datatransmission, tone generation and detection, encoding, decoding,signaling and signal processing and other functional aspects of the datacommunication system (and components of the individual operatingcomponents of the system) may not be described in detail herein.Furthermore, the connecting lines shown in the various figures containedherein are intended to represent exemplary functional relationshipsand/or physical couplings between the various elements. It should benoted that many alternative or additional functional relationships orphysical connections may be present in a practical communication system.

[0047]FIG. 2 illustrates a block diagram of an exemplary communicationsystem, including host 250, and modem 210 for use to enable host 250 tocommunicate over telephone line 205. As stated above, use of a computeras a host or a telephone line as a communication medium to describedifferent embodiments of the present application is merely exemplary. Infact, various embodiments of the present invention can be implementedfor use by any host, such as a computer, set-top box, game console, orany other device or system that may utilize a modem of the presentinvention to communicate via any communication medium, such as telephoneline 205, a cable line, a power line, or any other communication channelsuitable for modem communication. Other possible hosts can be alarmsystems, remote control systems, monitoring systems, cameras,residential and professional gateways, television sets, radios, displaypanels, facsimile machines, answering machines, wired telephones,cordless telephones, cellular telephones, BlueTooth and wireless modemplugs, Internet appliances, etc.

[0048] As shown, modem 210 includes digital isolation barrier (“DIB”)220, which is coupled in between line side circuitry 215 and modemconnector 230. Digital isolation barrier 220, which will be discussed inmore detail in conjunction with FIG. 3A, provides electrical isolationbetween line side circuitry 215 and modem connector 230. Line sidecircuitry 215 operates with a floating ground reference, and cantolerate high voltage inputs for operation with telephone 205 andtypical surge requirements. Modem connector 230, however, operates witha fixed digital ground and utilizes standard CMOS logic levels. Asshown, in the present embodiment, modem connector 230 is connected todigital isolation barrier 220 via four wires 221-224. As it should beappreciated, unlike the embodiment described in FIG. 1 of U.S. Pat. No.6,351,530, for example, modem 210 of the present embodiment does notinclude a digital isolation barrier interface between digital isolationbarrier 220 and modem connector 230. In other words, digital isolationbarrier 220 is connected to modem connector 230 without a digitalisolation barrier interface as an intermediary.

[0049] It should be noted that the number of wires between (1) line sidecircuitry 215 and digital isolation barrier 220, (2) digital isolationbarrier 220 and modem connector 230, or (3) modem connector 230 and host250, may vary from embodiment to embodiment, and various embodiments ofthe present invention may be implemented using any number of wires, e.g.1 through n. Accordingly, use of four wires is merely exemplary.

[0050] In the embodiment shown, modem connector 230 includes connectorpins 231, which can be received by slots 241 of host bus/connector 240.Modem connector 230 and host bus 240 provide a one-to-one connectivitybetween lines 221-224 of modem 210 and lines 251-254 of host 250. Fourwires 221-224 of digital isolation barrier 220 include clock and powersignal lines 221 and 222, as well as data and control signal lines 218and 219, which coordinate bi-directional transfer of data, control andprogramming signals across digital isolation barrier 220. Through hostbus 240 and modem connector 230, modem 210 shares a common ground andpower supply with host 250.

[0051] Line side circuitry 215, which will be discussed in more detailin conjunction with FIG. 4, includes modem side DIB interface 212 forinterfacing line side circuitry 215 with digital isolation barrier 220.As shown, four lines 216-219 provide connectivity between digitalisolation barrier 220 and line side circuitry 215. Four lines 216-219have a one-to-one correspondence with lines 221-224, which werediscussed above.

[0052] Turning to host 250, which will be discussed in more detail inconjunction with FIG. 5, it includes host side DIB interface 260 forinterfacing host 250 with digital isolation barrier 220 through host bus240 and modem connector 230. As shown, host side DIB interface 260 isconnected to host bus or connector 240 via four lines 251-254, whichcorrespond to four lines 221-224 of digital isolation barrier 220. Host250 further includes host side modem processing 270, which may be anyone of modem configurations described in FIG. 1. For example, in oneembodiment, host side modem processing 270 may include a controller anda DSP, and perform as controller-based modem 100. Yet, in anotherembodiment, host side modem processing 270 may include a DSP, and becontrolled by a host controller (not shown) in order to perform as acontrollerless modem 120. In some embodiments, host side modemprocessing 270 may not exist, in which configuration, a host controller(not shown) controls host side DIB interface 260 and other modem and DSPoperations, in order to function as soft modem 120. As stated above, itshould be noted that modem connector 230 or host bus/connector 240 canbe any type of conductor or channel that is capable of providing acommunication path.

[0053] As one of the advantages of modem 210, for example, worldwidehomologation costs and delays will be substantially reduced, due to thefact, once approved, modem 210 can be utilized in accordance to anyexisting configuration (such as controller-based modem, controllerlessmodem or soft modem) or in any host, without requiring suchconfiguration or host to be re-homologated. Furthermore, modem 210 hassubstantially less number of components compared to existing modems.Because modem 210 can provide a macro-component for adapting thecommunication line to the host, the need for expert knowledge by modemmanufacturers with respect to safety requirements, such aselectromagnetic compatibility/electromagnetic interference (“EMC/EMI”),will be lessened. As a result of a faster homologation process,reduction in the number of configurations and hosts to be homologated,reduction in engineering burden and expert knowledge, modem 210manufacturers may save significant cost and substantially shorten theirtime to market.

[0054]FIG. 3A illustrates exemplary modem 310, including line sidecircuitry 315 and digital isolation barrier 320, according to oneembodiment of the present invention. As shown, digital isolation barrier320 is connected to modem connector 330 via four lines 321-324 at oneside, and at the other side, digital isolation barrier 320 is connectedto line side circuitry 315 via four lines 316-319. In the embodimentshown, digital isolation barrier 320 includes a transformer 326 forcommunicating clock and power signals from modem connector 330 to modemside DIB interface 312 of line side circuitry 315 via lines 321-322 and316-317. More specifically, the primary side of transformer 326, i.e.lines 321-322, is driven by modem connector 330 (when connected to ahost), such that clock and power signals of sufficient strength can bederived from the secondary side of the transformer 326, i.e. lines316-317. The clock signal, if provided, is coupled to line sidecircuitry 315 via a relatively small value capacitor (not shown). Thepower connections of line side circuitry 315 may be coupled to thesecondary side of transformer 326 via a half wave rectifier comprising avoltage regulating diode (not shown) and a charge storage capacitor (notshown). The capacitor is provided across the power and groundconnections of line side circuitry 315 to provide a stable power supplyvoltage. Although the above-described embodiment employs a half waverectifier, a full wave rectifier or a bridge rectifier could also beutilized.

[0055] Digital isolation barrier 320 also includes a differentialconfiguration involving two capacitors 327 and 328. In this embodiment,a serial datastream including data, control and/or programming signalsare communicated across a data path provided by two capacitors 327 and328. In some embodiments, a differential bi-directional line providing abi-directional transmit/receive path, may be implemented using aseparate receive data path and a transmit data path. In one embodiment,two capacitors 327 and 328 may be replaced by a single capacitor, inwhich event the serial datastream are communicated across a signal pathemploying the single capacitor (not shown). In yet another embodiment,digital isolation barrier 320 may include an isolation transformer (notshown) to replace capacitors 327 and 328. As a result, data, controland/or programming signals may be communicated between line sidecircuitry 315 and modem connector 330. One of ordinary skill in the artwould know that other types of circuitry (such as opto-couplers andthermal relay circuitry) may be used to effect digital isolation barrier320, in accordance with the present invention. Furthermore, digitalisolation barrier 320 may include transformers, capacitors or any othercomponents that can satisfy the requirements of an isolation betweenTelephone Network Voltage (“TNV”) and Safety Extra Low Voltage (“SELV”)circuits as defined in Safety Standard IEC60950, which are herebyincorporated by reference, or other similar standards.

[0056] It should be noted that in some embodiments, four lines 321-324and 316-319 may be reduced to single lines 324 and 319, respectively,wherein, as described above, a single capacitor provides the serialdatastream across a signal path including lines 324 and 319. Yet, inanother embodiment, four lines 321-324 and 316-319 may be reduced todouble lines 323-324 and 318-319, respectively, wherein, as describedabove, two capacitors provide the serial datastream across a pathincluding lines 323-324 and 318-319.

[0057]FIG. 3B is a diagram of an exemplary frame protocol forcommunicating information across digital isolation barrier 320 of FIG.3A in accordance with one embodiment of the present invention. Becausedigital isolation barrier 320 is composed of devices such as capacitorsor transformers, DC signals cannot be transmitted across digitalisolation barrier 320 and communications are achieved via AC signals. Inthe present embodiment, an encoding scheme is used to eliminate longsequences of zeros or ones in the data. It should be noted that variousprotocols or signaling techniques may be used to communicate data acrossdigital isolation barrier 320 to line side circuitry 315 or a host (viamodem connector 330) and the serial protocol described below is merelyexemplary.

[0058] The serial protocol provides sufficient bandwidth to accommodatedata from various data, control and status signals of line sidecircuitry 315. It is also contemplated that errors (such as those due tovoltage surges) may be accounted for by error correction techniques. Onemethod of detecting such errors is to include redundancy in thetransmitting data, such as providing a separate, redundant data packetfor each data packet that is transmitted.

[0059] The exemplary frame 350 is composed of a number of components orbit groupings. Specifically, frame synchronization bits 352 are providedto coordinate communications between the host and line side circuitry315. In one embodiment, frame synchronization bits 352 are provided bythe host. Following frame synchronization bits 352, data, control and/orprogramming bits 354 are transmitted from the host across modemconnector 230 and digital isolation barrier 320 to line side circuitry315. In the present embodiment, in which bi-directional serialcommunications across digital isolation barrier 320 are utilized, anumber of reversal bits 356 are provided in order to allow sufficienttime for transceiver circuitry 435 of modem side DIB interface 430 (seeFIG. 4) and transceiver circuitry 535 of host side DIB interface 530(see FIG. 5) to switch direction. The number of bits required depends onthe switching time of the particular transceiver circuitry utilized. Aspecific reversal synchronization pattern may be utilized to initiatereversal of the transceiver circuitry.

[0060] Next, data, control and/or programming bits 358 are communicatedin a serial manner from line side circuitry 315 to the host via modemconnector 330. Idle bits 360 are also provided in the serial frame 350to provide extra bandwidth (in a predefined frame size) for addition ofother capabilities and information. The data, control and/or programmingbits 358 may also include interrupt-type information for use incommunicating status changes and/or synchronization.

[0061] In one embodiment, the encoding protocol involves transmittingdata across the digital isolation barrier 320 at half of the clock rate.According to such scheme, a “0” is coded as a logic level low to a logiclevel high transition, while a “1” is coded as a transition from a logiclevel high to a logic level low transition. For example, if a 4 MHzclock is provided to line side circuitry 315, a 2 MHz signal derivedfrom the clock signal may be used as a bit clock for serialcommunications. Using this arrangement, 128 bits are available in serialform during one period of a 16 kHz sample rate with a 2.048 MHz clock(128=4.096 MHz/(2*16 kHz)).

[0062] Turning to FIG. 4, it illustrates exemplary modem 410, includingline side circuitry 410 and digital isolation barrier 450, according toone embodiment of the present invention. As shown, line side circuitry410 includes modem side DIB interface 430 and telephone line circuitry420. According to one embodiment, modem side DIB interface 430 iscoupled to telephone line circuitry 420 at one side, and connected todigital isolation barrier 450 at the other end. In one embodiment, modemside DIB interface 430 is connected to digital isolation barrier 450 viafour lines, which are received by power/clock 434 and transceiver 435.As discussed above, modem side interface 430 may be connected to digitalisolation barrier 450 via a single wire or two wires, which can bereceived by transceiver 435. Accordingly, in some embodimentspower/clock 434 is optional. Modem side DIB interface 430 furtherincludes a protocol framing/control circuit 436 that functions toorganize the data transmitted by transceiver 435. Protocolframing/control circuit 436 also deconstructs signals received bytransceiver 435 from the host via modem connector 460.

[0063] As shown, modem side DIB interface 430 also includes codec(coder/decoder) 431, DAC (digital-to-analog converter) 432, ADC(analog-to-digital converter) 433 and a memory (not shown), which, insome embodiments, may store code for execution by modem side DIBinterface 430 or may store electrical specifications and configurationsrelating to the regulatory requirements of various countries. In oneembodiment, codec 431 may be a 16 bit/16 kHz second order sigma-deltacodec used for sampling analog signals on telephone line 405, orproviding such signals to telephone line 405. DAC 432 is utilized forconverting digital data, received via transceiver 435, to analog datafor transmission to telephone line 405 via codec 431. In addition, ADC433 is utilized for converting analog data, received from telephone line405 via codec 431, for transmission to modem connector via transceiver435. It should be noted that in some embodiments, DAC 432 and ADC 433may operate as part of codec 431, or may be separate circuits for use byother components of line side circuitry 410. For example, DAC 432 may beutilized by ring/LPR detection circuitry 423. Similarly, ADC 433 mayoperate in conjunction with measurement circuitry 426, which may includetip/ring voltage measurement and loop current measurement.

[0064] Telephone line circuitry 420 may include a variety of circuitsdepending upon the number of features provided by modem 400. Forexample, telephone line circuitry 420 may include caller ID 421, whichis capable of receiving and decoding caller identification informationfrom telephone line 406. Accordingly, caller ID 421 may include arelatively simple ADC and a demodulator complying with one or morestandards (e.g., V.23/Bell 202, ETSI 300778 series). Caller ID 421 mayalso be capable of transferring caller identification information acrossdigital isolation barrier 450 in a low power state, and can beprogrammable to provide caller ID information with a ring or linepolarity reversal as alert signal.

[0065] Telephone line circuitry 420 further includes line driver 422 forproviding signals to telephone line 405. Line driver 422 may beprogrammable to drive signals having the electrical characteristicsprescribed by the country in which modem 400 is being used. Telephoneline circuitry 420 may also include programmable line/ring impedance427, which is provided to allow modem 400 or the host to program theelectrical characteristics of modem 400 as seen by telephone line 405 tofacilitate compliance with a variety of regulatory standards, includingcountry-by-country ring loading.

[0066] In addition, programmable measurement circuitry 426 may beprovided with adjustable parameters for measuring tip/ring voltage andloop current conditions on telephone line 405. Ring/line polarityreversal (LPR) detect 423 may also be programmable to comply with bothU.S. and international requirements. Ring/LPR detect 423 functions toprovide ring and ring wake bit signals. In addition, ring/LPR detect 423is configurable to provide line current sensing information for use byremote on-hook 424 and extension off-hook 425.

[0067] In some embodiments of the present invention, modem 400 isdesigned to operate in a predetermined number of countries and telephoneline circuitry 420 is not programmable for unintended regions/countries.For example, according to one aspect of the present invention, modem 400can be provided in three defined and region/countries specificconfigurations, wherein in one configuration, modem 400 is operable inNordic European countries only; in a second configuration, modem 400 maybe configured to operate in the rest of Europe, India and Japan only;and in a third configuration, modem 400 may be configured to operate inthe remaining countries.

[0068]FIG. 5 illustrates an exemplary embodiment of host 510, accordingto one embodiment of the present invention. As shown, host 510 includeshost side DIB interface 530 and host side modem processing 520.According to one embodiment, host side DIB interface 530 is coupled tohost side modem processing 520 at one side, and connected to hostbus/connector 560 at the other end. Host bus 560 is capable of beingconnected to modem connector 460, which is in communication with modemside DIB interface 430. In one embodiment, host side DIB interface 530is connected to host bus 560 via four lines, which are received bypower/clock 534 and transceiver 535. As discussed above, host side DIBinterface 530 may be connected to host bus 560 via a single wire or twowires, which can be received by transceiver 535. Accordingly, in someembodiments power/clock 434 is optional. Host side DIB interface 530further includes a protocol framing/control circuit 536 that functionsto organize the data transmitted by transceiver 535. Protocolframing/control circuit 536 also deconstructs signals received bytransceiver 535 from the modem via host bus 560.

[0069] Host side modem processing 520 may include DSP 521, controller522, software 523 and memory 524. For example, to support controllerlessmodem 120, host side modem processing 520 would include DSP 521, andsoftware 523 and memory 524 for use by DSP 521. In such event, a hostcontroller (not shown), such as an Intel processor on a computermotherboard provides controller functions using a modem controllersoftware residing in the computer memory. Alternatively, to function assoft modem 120, host side modem processing 520 is eliminated, such thata host controller (not shown) can perform controller and DSP functionsusing a modem controller and DSP software residing in the computermemory. As another example, to support controller-based modem 110, hostside modem processing 520 would include controller 522 and DSP 521, andsoftware 523 and memory 524 for use by controller 522 and DSP 521. Insuch event, software 523 would support various modem DSP functions, suchas V.92, V.90, V.34, V.32, etc. modulation techniques, and modemcontroller functions, such as V.42 error correction, and V.42bis datacompression, etc.

[0070] In one exemplary embodiment of the present invention, followingthe application of power to modem 400, modem 400 enters an optionalsleep or listen mode. Next, modem 400 determines if a synchronizationpacket has been received from host 510 via digital isolation barrier450. If so, modem 400 exits sleep mode, else line side circuitry 410determines if an interrupt has been generated by any of telephone linecircuitry 420 connected to telephone line 405. If an interrupt has beenreceived, modem 400 exits sleep mode and a signal is then communicatedto host 510 to request synchronization. After exiting modem sleep mode,modem 400 determines if synchronization with host 410 has been achieved.If not, a timeout counter is examined to determine if a predeterminedamount of time has expired without synchronization. If the predeterminedamount of time has not expired, the synchronization process describedabove continues. If the time-out value has been reached, or if aninterrupt has not been received, modem 400 may enter an optional sleepor listen mode.

[0071] Similarly, following the application of power to host 510, host510 enters a wake-up or resynchronization mode. Next, transceiver 535transmits a synchronization packet to modem 400 across modemconnector-460. Host 510 then awaits signals from modem 400 indicatingthat synchronization has been achieved. If synchronization is notachieved, a counter is examined to determine if a predetermined time-outvalue has reached. If the timeout value has surpassed, an additionalsynchronization packet may be transmitted. If synchronization isachieved, serial data, control and/or programming signals aretransmitted or received by transceivers 435 and 535. Followingcompletion of the serial communications, an optional low power mode isentered, where host 510 enters a sleep mode and awaits a wake-up signalor service request from modem 400.

[0072] It should be noted that in some embodiments, for example, whenmodem 400 is utilized in a game console or a set-top box, as host 510,modem 400 and/or host 510 may not include a sleep mode, and remain inactive mode after the application of power. Furthermore, one of ordinaryskill in the art would realize that there are a variety of ways toachieve a connection between or synchronize modem 400 and host 510 afterthe application of power.

[0073]FIG. 6 illustrates a block diagram of an exemplary modem of thepresent invention for connection to a communication card, such as a PCIcard, an AMR card, a CNR card, an ACR card, etc. As shown, modem 600 isattached to PC bracket 601, which is a typical square bracket used toadd peripheral components to a personal computer. PC bracket 601 exposesRJ-11 jack 602 of modem 600 to the outside of the personal computer forreceiving a telephone line (not shown). Modem 600 also includes lineside circuitry 604, similar to line side circuitry 410 of FIG. 4, anddigital isolation barrier 606, similar to digital isolation barrier 320of FIG. 3A. Line side circuitry 604 is in communication with thetelephone line via RJ-11 jack 602, and digital isolation barrier 606isolates line side circuitry 604 from modem connector 607. As shown,modem cable 610, with cable connectors 611 and 612 at each end, providesconnectivity between PCI card 620 and modem 600. In one embodiment,modem cable 610 provides a two-wire path for control/data signal and atwo-wire path for power/clock signals. As discussed above, in variousembodiments of the present invention, modem cable 610 may be a one-wire,two-wire, three-wire or n-wire cable. For example, in a two-wire modemcable, the two wires provide a path for data/control. In otherembodiments, additional wires may be added to provide additionalsignals, such as a ground signal.

[0074] As shown, PCI card 620 includes PCI connector 622 for receivingcable connector 612 and for connecting digital isolation barrier 606 ofmodem 600 to host side DIB interface 624, similar to host side DIBinterface 530 of FIG. 5. PCI card 620 also includes PCI bus connector620, which can be plugged into one of PCI bus slots (not shown) of thepersonal computer. It should be noted that PCI card 620 may include acontroller, a DSP and a memory with software to provide acontroller-based modem, or may include a DSP and a memory with softwareto provide a controllerless modem being controlled by a host processorin the personal computer, or may merely route wires from host side DIBinterface 624 to PCI bus connector 626 to provide a connection betweenthe host processor and modem 600.

[0075]FIG. 7 illustrates a block diagram of an exemplary modem 700 ofthe present invention for connection to a computer motherboard. Modem700, including RJ-11 jack 702, line side circuitry 704 and digitalisolation barrier 706 correspond to modem 600, including RJ-11 jack 602,line side circuitry 604 and digital isolation barrier 606 of FIG. 6,respectively. As shown, modem 700 may be attached to PC bracket 701,which corresponds to PC bracket 601 of FIG. 6. Modem 700 furtherincludes modem connector 712, which is capable of being plugged into PCDIB bus 722 on PC motherboard 720. Although not shown, PC motherboard720 also includes a host side DIB interface, similar to host side DIBinterface 624, which provides an interface between PC DIB bus 722 and aPC or host processor (not shown). Accordingly, a communication path isprovided between the host processor and digital isolation barrier 706 ofmodem 700 via the host side DIB interface, PC DIB bus 722 and modemconnector 707.

[0076] As discussed above, modem cable 710 may be a one-wire, two-wire,three-wire, four-wire (such as the present embodiment) cable, or provideadditional wires for providing more signals between modem 700 and PC DIBbus 722. Accordingly, PC DIB bus may vary in size. In the exemplaryembodiment of FIG. 7, PC DIB bus 722 may include four connectors toreceive two wires for data/control and two wires for power/clock. PC DIBbus 722 may also include an additional wire for a ground signal.However, in some embodiments, PC DIB bus 722 may include only one or twoconnectors for receiving data/control.

[0077]FIG. 8A illustrates a full front view of an exemplary modem 800 ofthe present invention, wherein modem components 810 are populated ontelephone line jack 803, such as an RJ-11 jack. As shown, modem 800includes telephone line jack 803 having telephone line receiver 805 withan opening to receive a telephone line. The opening defines a number ofwalls in telephone line jack 803. As shown, modem components 810 may bepopulated on one or more of the walls. In one embodiment, modemcomponents include a line side circuitry, similar to line side circuitry704, coupled to telephone line receiver 805 for connection to atelephone line. Further, modem 800 includes a digital isolation barrier,similar to digital isolation barrier 706, for isolating the line sidecircuitry and the telephone line from a modem connector, such as modemconnector 707, which is capable of being connected to a host.

[0078]FIG. 8B illustrates a top view of an exemplary modem 820 of thepresent invention, wherein modem components are populated on a top wallof telephone line jack 822. As shown, the modem components includedigital isolation barrier 830, including two capacitors 832 and 834, andtransformer 836. Digital isolation barrier 830 is connected to modemconnector 825 at one end, and line side circuitry 840 at the other end.Further, line side circuitry 840 is connected to a phone line receiverof telephone line jack 822 via line 850. In some embodiments, such asthe embodiment of FIG. 8A, some of the modem components may be populatedon the side walls or the bottom wall of telephone line jack 822.Further, digital isolation barrier 830 may include less components, asdiscussed above in conjunction with FIG. 3A.

[0079]FIG. 9 illustrates a block diagram of an exemplary modem of thepresent invention for connection to combo card 920, such as a LAN card,audio card, BlueTooth card, Ethernet card, etc. As shown, modem 900 maybe attached or plugged into to combo card 920, which is attached to PCbracket 901. PC bracket 901 is a typical square bracket used to addperipheral components to a personal computer and, as shown, can exposemodem communication jack 902, such as RJ-11 jack, and combocommunication jack 922, such as RJ-45 jack, to the outside of thepersonal computer for receiving communication lines (not shown). Modem900 also includes line side circuitry 904 and digital isolation barrier906. Line side circuitry 904 can be placed in communication with acommunication line via modem communication jack 902, and digitalisolation barrier 906 isolates line side circuitry 904 from modemconnector 908. As shown, modem connector 908 may be connected to orplugged into combo card connector 909, which provide connectivitybetween combo card 920 and modem 900. As shown, line side circuitry 905and digital isolation barrier 906 communicate via line 905. Also,digital isolation barrier 906 communicates with combo card 920 via lines907 and connectors 908 and 900. As stated above, lines 905, and 907 mayinclude any number of wires, e.g. 1-n wires.

[0080] In one embodiment, combo card 920 may include a host side DIBinterface (not shown) for communication with digital isolation barrier906. In other embodiments, however, combo card 920 may route line 907,received via connectors 908 and 909, to combo card connector bus 924. Insuch embodiments, the personal computer would include host side DIBinterface (not shown), rather than combo card 920.

[0081] The methods and systems presented above may reside in software,hardware, and/or firmware on the device, which can be implemented on amicroprocessor, digital signal processor, application specific IC, orfield programmable gate array (“FPGA”), or any combination thereof,without departing from the spirit of the invention. Furthermore, thepresent invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive.

What is claimed is:
 1. A modem system for use to enable a host tocommunicate over a communication line, said host having a hostconnector, said modem system comprising: a line side circuitry capableof interfacing with said communication line; a digital isolation barrier(DIB) coupled to said line side circuitry; and a modem connectorconnected to said digital isolation barrier and capable of connectingsaid digital isolation barrier to said host connector, wherein saiddigital isolation barrier isolates said modem connector from said lineside circuitry.
 2. The modem system of claim 1, wherein said line sidecircuitry includes a line side DIB interface for communication with saiddigital isolation barrier.
 3. The modem system of claim 1, wherein saiddigital isolation barrier is coupled to said line side circuitry via aplurality of lines including two lines of data/control and two lines ofpower/clock.
 4. The modem system of claim 3, wherein said plurality oflines include a ground line.
 5. The modem system of claim 1, whereinsaid modem connector is connected to said digital isolation barrier viaa plurality of lines including two lines of data/control and two linesof power/clock.
 6. The modem system of claim 5, wherein said pluralityof lines include a ground line.
 7. The modem system of claim 1, whereinsaid modem connector is connected to said digital isolation barrier viaa single differential pair of lines of data/control.
 8. The modem systemof claim 7, wherein said modem connector is connected to said digitalisolation barrier via said single differential pair of lines ofdata/control and one ground line.
 9. The modem system of claim 1,wherein said modem connector is connected to said digital isolationbarrier via a plurality of differential pair of lines of data/control.10. The modem system of claim 9, wherein said modem connector isconnected to said digital isolation barrier via said plurality ofdifferential pair of lines of data/control and one ground line.
 11. Themodem system of claim 1, wherein said modem connector is connected tosaid digital isolation barrier via a single line of data/control. 12.The modem system of claim 11, wherein said modem connector is connectedto said digital isolation barrier via said single line of data/controland one ground line.
 13. A modem device for use to enable a host tocommunicate over a communication line, said host having a hostconnector, said modem device comprising: a line side circuitry capableof interfacing with said communication line; and a digital isolationbarrier (DIB) coupled to said line side circuitry, said digitalisolation barrier capable of being connected to a modem connector forconnection to said host connector, wherein said digital isolationbarrier is capable of isolating said modem connector from said line sidecircuitry.
 14. The modem device of claim 13, wherein said line sidecircuitry includes a line side DIB interface for communication with saiddigital isolation barrier.
 15. The modem device of claim 13, whereinsaid digital isolation barrier is coupled to said line side circuitryvia a plurality of lines including two lines of data/control and twolines of power/clock.
 16. The modem device of claim 15, wherein saidplurality of lines include a ground line.
 17. The modem device of claim13, wherein said digital isolation barrier is capable of being connectedto said modem connector via a plurality of lines including two lines ofdata/control and two lines of power/clock.
 18. The modem device of claim17, wherein said plurality of lines include a ground line.
 19. The modemdevice of claim 13, wherein said digital isolation barrier is capable ofbeing connected to said modem connector via two lines of data/controland two lines of power/clock.
 20. The modem device of claim 13, whereinsaid digital isolation barrier is capable of being connected to saidmodem connector via a single differential pair of lines of data/control.21. The modem device of claim 20, wherein said modem connector isconnected to said digital isolation barrier via said single differentialpair of lines of data/control and one ground line.
 22. The modem deviceof claim 13, wherein said modem connector is connected to said digitalisolation barrier via a plurality of differential pair of lines ofdata/control.
 23. The modem device of claim 22, wherein said modemconnector is connected to said digital isolation barrier via saidplurality of differential pair of lines of data/control and one groundline.
 24. The modem device of claim 13, wherein said digital isolationbarrier is capable of being connected to said modem connector via asingle line of data/control.
 25. The modem device of claim 24, whereinsaid digital isolation barrier is capable of being connected to saidmodem connector via said single line of data/control and one groundline.
 26. A modem system for use to enable a host to communicate over acommunication line, said host having a host connector, said modem systemcomprising: a communication line receiver having an opening forreceiving said communication line, said opening defining a plurality ofside walls; a line side circuitry capable of interfacing with saidcommunication line receiver; and a digital isolation barrier (DIB)coupled to said line side circuitry, said digital isolation barriercapable of being connected to a modem connector, wherein said digitalisolation barrier isolates said modem connector from said line sidecircuitry; wherein said modem connector is capable of being connected tosaid host connector, and wherein said line circuitry and said digitalisolation barrier populate one or more of said plurality of side walls.27. The modem system of claim 26, wherein said digital isolation barrieris connected to said modem connector.
 28. The modem system of claim 26,wherein said modem connector is connected to said host connector. 29.The modem system of claim 26, wherein said line side circuitry includesa line side DIB interface for communication with said digital isolationbarrier.
 30. The modem system of claim 26, wherein said digitalisolation barrier is coupled to said line side circuitry via a pluralityof lines including two lines of data/control and two lines ofpower/clock.
 31. The modem system of claim 31, wherein said plurality oflines include a ground line.
 32. The modem system of claim 26, whereinsaid modem connector is connected to said digital isolation barrier viaa plurality of lines including two lines of data/control and two linesof power/clock.
 33. The modem system of claim 32, wherein said pluralityof lines include a ground line.
 34. The modem system of claim 26,wherein said modem connector is connected to said digital isolationbarrier via a single differential pair of lines of data/control.
 35. Themodem system of claim 34, wherein said modem connector is connected tosaid digital isolation barrier via said single differential pair oflines of data/control and one ground line.
 36. The modem system of claim26, wherein said modem connector is connected to said digital isolationbarrier via a plurality of differential pair of lines of data/control.37. The modem system of claim 36, wherein said modem connector isconnected to said digital isolation barrier via said plurality ofdifferential pair of lines of data/control and one ground line.
 38. Themodem system of claim 26, wherein said modem connector is connected tosaid digital isolation barrier via a single line of data/control. 39.The modem system of claim 38, wherein said modem connector is connectedto said digital isolation barrier via said single line of data/controland one ground line.
 40. A modem connector for connecting a modem to ahost, wherein said modem includes a digital isolation barrier (DIB)coupled to a line side circuitry for communication with a communicationline, said modem connector comprising: a data line for communicatingdata between said modem and said host; a clock line for clocking saiddata between said modem and said host; and a power line for providingpower from said host to said modem; wherein said data line, said clockline and said power line are capable of being connected to said digitalisolation barrier, which is capable of isolating said modem connectorfrom said line side circuitry.
 41. The modem connector of claim 40,wherein said data line includes a transmit path and a receive path. 42.The modem connector of claim 40, wherein said data line is abi-directional path.
 43. The modem connector of claim 40, wherein saidhost includes a host side DIB interface, and said modem connectorprovides said lines to host DIB interface.
 44. The modem connector ofclaim 40 further comprising a four-wire cable including said lines. 45.The modem connector of claim 40 further comprising a ground line.
 46. Amodem connector for connecting a modem to a host, wherein said modemincludes a digital isolation barrier (DIB) coupled to a line sidecircuitry for communication with a communication line, said modemconnector consisting of: a data line for communicating data between saidmodem and said host; a clock line for clocking said data between saidmodem and said host; and a power line for providing power from said hostto said modem; wherein said data line, said clock line and said powerline are capable of being connected to said digital isolation barrier,which is capable of isolating said modem connector from said line sidecircuitry.
 47. The modem connector of claim 46, wherein said data lineincludes a transmit path and a receive path.
 48. The modem connector ofclaim 46, wherein said data line is a bi-directional path.
 49. The modemconnector of claim 46, wherein said host includes a host DIB interface,and said modem connector provides said lines to host side DIB interface.50. A host connector for communication with a modem, said modemincluding a digital isolation barrier (DIB) coupled to a line sidecircuitry for communication with a communication line, said hostconnector comprising: a data line for communicating data between saidmodem and said host; a clock line for clocking said data between saidmodem and said host; and a power line for providing power from said hostto said modem; wherein said data line, said clock line and said powerline are capable of being connected to said digital isolation barrier,which is capable of isolating said host connector from said line sidecircuitry.
 51. The host connector of claim 50, wherein said data lineincludes a transmit path and a receive path.
 52. The modem connector ofclaim 50, wherein said data line is a bi-directional path.
 53. The hostconnector of claim 50, wherein said host includes a host side DIBinterface, and said host connector provides said lines to host DIBinterface.
 54. The modem connector of claim 50 further comprising aground line.
 55. A communication system capable of communicating over acommunication line, said communication system comprising: a modemincluding a line side circuitry capable of being connected to saidcommunication line, a digital isolation barrier (DIB) coupled to saidline side circuitry and a modem connector coupled to said digitalisolation barrier; and a host including a modem connector receiving saidmodem connector, a host side DIB interface coupled to said modemconnector, and a host processor coupled to said host side DIB interface;wherein said host processor controls said modem.
 56. The communicationsystem of claim 55, wherein said line side circuitry includes a lineside DIB interface for communication with said digital isolationbarrier.
 57. The communication system of claim 55, wherein said digitalisolation barrier is coupled to said line side circuitry via a pluralityof lines including two lines of data/control and two lines ofpower/clock.
 58. The communication system of claim 57, wherein saidplurality of lines include a ground line.
 59. The communication systemof claim 55, wherein said modem connector is connected to said digitalisolation barrier via a plurality of lines including two lines ofdata/control and two lines of power/clock.
 60. The communication systemof claim 59, wherein said plurality of lines include a ground line. 61.The communication system of claim 55, wherein said modem connector isconnected to said digital isolation barrier via a single differentialpair of lines of data/control.
 62. The communication system of claim 61,wherein said modem connector is connected to said digital isolationbarrier via said single differential pair of lines of data/control andone ground line.
 63. The communication system of claim 55, wherein saidmodem connector is connected to said digital isolation barrier via aplurality of differential pair of lines of data/control.
 64. Thecommunication system of claim 63, wherein said modem connector isconnected to said digital isolation barrier via said plurality ofdifferential pair of lines of data/control and one ground line.
 65. Thecommunication system of claim 55, wherein said modem connector isconnected to said digital isolation barrier via a single line ofdata/control.
 66. The communication system of claim 65, wherein saidmodem connector is connected to said digital isolation barrier via saidsingle line of data/control and one ground line.
 67. A communicationsystem capable of communicating over a communication line, saidcommunication system comprising: a modem including a line side circuitrycapable of being connected to said communication line, a digitalisolation barrier (DIB) coupled to said line side circuitry and a modemconnector coupled to said digital isolation barrier; and a hostincluding a communication card, said communication card having a modemconnector, for receiving said modem connector, and a host side DIBinterface coupled to said modem connector.
 68. The communication systemof claim 67, wherein said communication card is a PCI card.
 69. Thecommunication system of claim 67, wherein said communication card is anAMR card.
 70. The communication system of claim 67, wherein saidcommunication card is an ACR card.
 71. The communication system of claim67, wherein said communication card includes a controller, a DSP and amemory, wherein said controller controls said modem and DSP, and saidmemory includes software for execution by said controller.
 72. Thecommunication system of claim 67, wherein said communication cardincludes a DSP, and wherein said host includes a processor forcontrolling said modem and said DSP.
 73. The communication system ofclaim 67, wherein said host includes a processor for controlling saidmodem and functioning as a DSP.
 74. The communication system of claim67, wherein said line side circuitry includes a line side DIB interfacefor communication with said digital isolation barrier.
 75. Thecommunication system of claim 67, wherein said digital isolation barrieris coupled to said line side circuitry via a plurality of linesincluding two lines of data/control and two lines of power/clock. 76.The communication system of claim 75, wherein said plurality of linesinclude a ground line.
 77. The communication system of claim 67, whereinsaid modem connector is connected to said digital isolation barrier viaa plurality of lines including two lines of data/control and two linesof power/clock.
 78. The communication system of claim 77, wherein saidplurality of lines include a ground line.
 79. The communication systemof claim 67, wherein said modem connector is connected to said digitalisolation barrier via a single differential pair of lines ofdata/control.
 80. The communication system of claim 79, wherein saidmodem connector is connected to said digital isolation barrier via saidsingle differential pair of lines of data/control and one ground line.81. The communication system of claim 67, wherein said modem connectoris connected to said digital isolation barrier via a plurality ofdifferential pair of lines of data/control.
 82. The communication systemof claim 81, wherein said modem connector is connected to said digitalisolation barrier via said plurality of differential pair of lines ofdata/control and one ground line.
 83. The communication system of claim67, wherein said modem connector is connected to said digital isolationbarrier via a single line of data/control.
 84. The communication systemof claim 83, wherein said modem connector is connected to said digitalisolation barrier via said single line of data/control and one groundline.
 85. The communication system of claim 67, wherein saidcommunication card is a combo card.
 86. The communication system ofclaim 67, wherein said communication card is an Ethernet card.
 87. Thecommunication system of claim 67, wherein said communication card is anaudio card.
 88. A communication card capable of connecting a host to amodem, said communication card comprising: a card-modem connector; acard-host connector capable of being connected to said host; whereinsaid modem includes a line side circuitry capable of being connected toa communication line, a digital isolation barrier (DIB) coupled to saidline side circuitry and a modem connector coupled to said digitalisolation barrier, and wherein said card-modem connector is capable ofbeing connected to said modem connector.
 89. The communication card ofclaim 88, wherein said communication card is a combo card.
 90. Thecommunication card of claim 88, wherein said communication card is anEthernet card.
 91. The communication card of claim 88, wherein saidcommunication card is an audio card.
 92. The communication card of claim88, wherein said communication card is a PCI card.
 93. The communicationcard of claim 88, wherein said communication card is a PCI card.
 94. Thecommunication card of claim 88, wherein said communication card is anAMR card.
 95. The communication card of claim 88, wherein saidcommunication card is an ACR card.
 96. The communication card of claim88, wherein said communication card includes a controller, a DSP and amemory, wherein said controller controls said modem and DSP, and saidmemory includes software for execution by said controller.
 97. Thecommunication card of claim 88, wherein said communication card includesa DSP, and wherein said host includes a processor for controlling saidmodem and said DSP.
 99. The communication card of claim 88, wherein saidhost includes a processor for controlling said modem and functioning asa DSP.
 100. The communication card of claim 88, wherein said line sidecircuitry includes a line side DIB interface for communication with saiddigital isolation barrier.
 101. The communication card of claim 88,wherein said digital isolation barrier is coupled to said line sidecircuitry via a plurality of lines including two lines of data/controland two lines of power/clock.
 102. The communication card of claim 101,wherein said plurality of lines include a ground line.
 103. Thecommunication card of claim 88, wherein said modem connector isconnected to said digital isolation barrier via a plurality of linesincluding two lines of data/control and two lines of power/clock. 104.The communication card of claim 103, wherein said plurality of linesinclude a ground line.
 105. The communication card of claim 88, Whereinsaid modem connector is connected to said digital isolation barrier viaa single differential pair of lines of data/control.
 106. Thecommunication system of claim 105, wherein said modem connector isconnected to said digital isolation barrier via said single differentialpair of lines of data/control and one ground line.
 107. Thecommunication system of claim 88, wherein said modem connector isconnected to said digital isolation barrier via a plurality ofdifferential pair of lines of data/control.
 108. The communicationsystem of claim 107, wherein said modem connector is connected to saiddigital isolation barrier via said plurality of differential pair oflines of data/control and one ground line.
 109. The communication cardof claim 88, wherein said modem connector is connected to said digitalisolation barrier via a single line of data/control.
 110. Thecommunication card of claim 109 wherein said modem connector isconnected to said digital isolation barrier via said single line ofdata/control and one ground line.
 111. The communication card of claim88 further comprising a host side DIB interface, wherein said cardconnector is connected to said host side DIB interface.
 112. Thecommunication card of claim 88, wherein said host includes a host sideDIB interface coupled to a host connector, wherein said card-hostconnector is capable of being connected to said host connector.
 113. Thecommunication card of claim 88, wherein said host is a terminal, acomputer, a game console, or a set-top box.
 114. The communication cardof claim 88, wherein said communication line is a telephone line, acable line, or a power line.
 115. The communication card of claim 88,wherein said modem is an analog modem, a DSL modem, a cable modem, or anISDN terminal adapter.
 116. A modem connector for connecting a modem toa host, said modem connector comprising: a data line for communicatingdata between said modem and said host; wherein said modem includes aline side circuitry capable of interfacing with said communication line,a digital isolation barrier (DIB) coupled to said line side circuitry,said digital isolation barrier capable of being connected to said modemconnector for connection to said host connector, wherein said digitalisolation barrier is capable of isolating said modem connector from saidline side circuitry.
 117. The modem connector of claim 116, wherein saiddata line includes a transmit path and a receive path.
 118. The modemconnector of claim 116, wherein said data line is a bi-directional path.119. The modem connector of claim 116, wherein said host includes a hostside DIB interface, and said modem connector provides said lines to hostDIB interface.
 120. The modem connector of claim 116 further comprisinga cable including said data line.
 121. The modem connector of claim 116further comprising a ground line.
 122. A host connector for connecting amodem to a host, said host connector comprising: a data line forcommunicating data between said modem and said host; wherein said modemincludes a line side circuitry capable of interfacing with saidcommunication line, a digital isolation barrier (DIB) coupled to saidline side circuitry, said digital isolation barrier capable of beingconnected to said host connector for connection to said host, whereinsaid digital isolation barrier is capable of isolating said hostconnector from said line side circuitry.
 123. The host connector ofclaim 122, wherein said data line includes a transmit path and a receivepath.
 124. The host connector of claim 122, wherein said data line is abi-directional path.
 125. The host connector of claim 122, wherein saidhost includes a host side DIB interface, and said host connectorprovides said lines to host DIB interface.
 126. The host connector ofclaim 122 further comprising a cable including said data line.
 127. Thehost connector of claim 122 further comprising a ground line.